To examine the effects of various neurotransmittors on embryonic neural differentiation. To confirm the role of prostaglandins in autoneuralization. To probe the possible role of prostaglandins in normal embryonic neural differentiation. To gather statistical data on the percentage of binucleated goldfish melanocytes produced in the presence of cytochalasin B. To examine by electronmicroscopy the mechanism of carotenoid movement in goldfish xantophores. To isolate mutants of our Pseudomonas species with altered putrescine transaminase or succinic semialdehyde dehydrogenase. BIBLIOGRAPHIC REFERENCES: The Activation of Adrenal Cortex Mitochondrial Malic Enzyme by Ca23 and Mg2 plus, D.R. Pfeiffer and T.T. Tchen, Biochem 14, 89 (1975). Cyclic-AMP Induction of Neurodifferentiation in Cultures of Undetermined Presumptive Epiderm from Amphibian Embryos, H. Wahn, L. Lightbody, J.D. Taylor and T.T. Tchen, Science 188, 366-369, April 25, 1975.